Receptacle for wiring devices



A ril 19, 1966 c. E. M ROBERTS RECEPTACLE FOR WIRING DEVICES Filed Aug. 5, 1963 INVENTOR CHARLES EDWARD M ROBERTS PATENT AGENT States Patent 3,247,346 RECEPTACLE FOR WIRING DEVICES Charles E. McRoberts, Toronto, Ontario, Canada, assignor to.-Amalgamated Electric Corporation, Limited,

=- Toronto, Ontario, Canada I Filed Aug. 5, 1963, Ser. No. 299,757

7 Claims. (Cl. 200-133) ,This invention relates to a receptacle for wiring devices such as screw-in overcurrent devices like plug fuses, for example. More particularly, this invention relates to a receptacle composed of a number of parts which are adapted to be held together by only one fastening device. .Receptacles for screw-in overcurrent devices and the like in the pasthave been constructed of a number of parts held together by a number of different types of fastening devices,.and such wiring devices, generally speaking, have been. complex to manufacture and assemble.

It isone. object of this invention to provide a receptacle for screw-in. overcurrent devices and the like which is composed of a number of parts all held together by one fastening'device and which may be assembled easily.

. Another object of this invention is to provide a receptacle for screw-in overcurrent devices and the like which has :azbo'dy portion divided into two parts with recesses provided in both parts for holding the contacts of the receptacle in place when the parts are assembled together, and with means to inhibit twisting movement of one part of the body relative to the. other part.

A further object of this invention is to provide a receptacle for screw-in overcurrent devices and the like which is provided withv closure means closable over overcurrent devices carried by the receptacle and adapted to prevent removal of the overcurrent devices when the closure means are locked in closed position.

- A receptacle embodying this invention for screw-in overcurrentdevices such as plug fuses and the like has a body which includes side walls and a base. The body has openings therein which are positioned side-by-side and each of which is adapted to receive a screw-in overcurrent device such as a plug fuse. The body is divided longitudinally across the openings into two parts, each of which contains a part of each of the openings. First recess means are formed in the walls of the body defining each opening and in both of the parts. Second recess means are formed in the base beneath each of the openings and in both of the parts. A different first electrical contact is provided for each of the openings, as is a different second electrical contact. The first electrical contacts each are retained by a different one of the first recess means, while the second electrical contacts each are retained by a different one of the second recess means. The first and second electrical contacts each have first portions which are adapted to contact different terminals of screw-in overcurrent devices screwed into the openings and second portions adapted to make contact with conductors external to the receptacle. Means are provided for restraining twisting movement of the parts of the body relative to each other, and additional means are provided for retaining the parts together.

An important feature of this invention is that the means retaining the parts together is a single fastening device. L Another important feature of this invention is the provision of closable means carried by the receptacle and closable over screw-in overcurrent devices screwed into the openings in the body.

1 This invention will become more apparent from the following detailed description taken in conjunction with the appended drawings, in which:

FIGURE 1 is an exploded perspective view of a receptacle embodying this invention; and

i in the form of circular cavities.

FIGURE 2 is an assembled perspective view of the receptacle.

Referring to the figures, there is shown a receptacle 10 which comprises a body 11 moulded of any suitable strong, rigid, electrical insulating material. Body 11 has two openings 12 and 13 formed therein, these openings being Body 11 is divided longitudinally across openings 12 and 13 into two parts 11a and 11b respectively. It will be seen that each of parts 11a and 11b has a part of openings 12 and 13 formed therein. Openings 12 and 13 each are designed to accommodate a screw-in overcurrent device such as a plug fuse, for example. It will be seen that body 11 has side walls 14 and a base 15.

Annular recesses 16 are formed in walls 14 which define openings 12 and 13, one recess 16 being provided for each of openings 12 and 13 remote from base 15. Recesses 17 are formed in base 15 in both parts 11a and 11b and beneath openings 12 and 13. Each of recesses 17 has shoulders 21 and 22 formed on opposite sides thereof, a part of shoulder 22 in FIGURE 1 being broken away to more clearly illustrate recess 17. Each of recesses 17 is bounded by end walls 23 and 24 respectively.

As best shown in FIGURE 1, an opening 18 is provided in base 15 beneath each of openings 12 and 13 and extending between the bottom surface 19 of openings 12 and 13 and the bottom surface 20 of receptacle 10.

Passing through both parts 11a and 11b at the centre thereof is an aperture 25 which is counter sunk at 26 and also on the opposite side wall 14 from that shown in FIG- URE 1. Parts 11a and 1112 are retained together by a single fastening device such as a rivet or a nut and bolt 34, the bolt or rivet passing through aperture 25.

Both parts 11a and 11b have projections 27 extending upwardly therefrom which, when the parts are assembled, as shown in FIGURE 2, form a handle 27.

Both parts 11a and 11b contain circular grooves 28 therein, while both of these parts also have tongues 30 (only one shown) projecting therefrom which engage in grooves 28 when parts 11a and 11b are assembled together. Furthermore, each of parts 11a and 1111 have tongues 31 projecting therefrom, each having an arm 32. These tongues and arms mate in corresponding grooves 33 (only one shown) formed in both members 11a and 11b. By reason of the mating engagement of tongues 30 and 31 in grooves 28 and 33, respectively, when parts 11a and 11b are assembled together as shown in FIGURE 2, relative twisting movement of the two parts with respect to each other is restrained.

Electrical contacts 35 are provided for each opening 12 and 13, these contacts being retained in different ones of recesses 16 and being precluded from movement by engagement with the shoulders 16a of recesses 16. A first portion 36 of each of contacts 35 is ring-shaped and has a screw thread 37 formed therein. A second portion 38 of each of contacts 35 is generally hook-shaped in nature and is formed integral with ring 36. Hook-shaped portions 38 extend outwardly of receptacle 10 through openings 39 in side Walls 14 and are capable of making elgctrical contact with a conductor external to receptacle 1 Associated with each of openings 12 and 13 are electrical contacts 40 which are generally U-shaped in nature, the arms of the U-shaped contacts forming prongs 41 and 42 which are joined by a bight 43 having a raised portion 44- therein. Projecting from bight 43 are tabs 45. Tabs 45 fit into recesses 17 in each of parts 11a and 11b and abut against end walls 23 and 24 and shoulders 21 and. 22. Bights 43, particularly raised portions 44 thereof, extend into openings 12 and 13 to establish contact between contacts 40 and the lower terminals of screw-in overcurrent devices screwed into openings 12 and 13, while ring-shaped portions 36 of contacts 35 eifect contact with the upper terminals of these screw-in devices, whereby, when screw-in overcurrent devices are screwed into openings 12 and 13, circuits are completed from hook-shaped portions 38 through ring-shaped parts 36, the upper terminals of the screw-in overcurrent devices, the overcurrent devices themselves, the lower terminals of the screw-in overcurrent devices, raised portions 44 and prongs 41 and 42.

As shown in both FIGURE-S l and 2, flaps 46 are hingeably mounted on receptacle 10, each flap being movable to a closed position where it covers an overcurrent device screwed into receptacle 10, as shown by the left-hand flap in FIGURE 2. Hook-shaped portions 38 of contacts 35 form the hinges for flaps 46, hookshaped portions 38 extending through openings 47 in flaps 46. Each of flaps 46 preferably is provided with an opening 48 through which one can view the state of an overcurrent device contained in the receptacle, i.e. whether it has blown or not.

In the assembly ofa receptacle embodying this invention, tabs 45 of contacts 40 are inserted in recesses 17 in part 11b. Hook-shaped portions 38 are hooked into engagement with flaps 46. These sub-assemblies then are mounted into position in part 11b with rings 36 in recesses 16 in the parts of openings 12 and 13 in part 1115, as is best shown in FIGURE 1. Following these steps, part 11a is placed over the sub-assembly so formed, so that the free tabs 45 of contacts 40 fit into the recesses 17 therein, the free parts of rings 36 fit into recesses 16 in the parts of openings 12' and 13 in part 11a, and mating engagement between the tongues and grooves is achieved. The receptacle then may be fastened together by the fastening device 34. When receptacle is so assembled, movement of contacts 35 is prevented by the engagement of ring-shaped parts 36 thereof with shoulders 16a, while movement of contacts 40 is similarly restrained by the insertion of tabs 45 in recesses 17.

It will be seen from the foregoing that a receptable embodying this invention, while it has a number of parts, is constructed so that all of these parts are retained together by one simple fastening device.

A receptacle embodying this invention is particularly suitable for use with an electrical load distribution serv ice centre of the type set out in copending application Serial No. 299,749, filed August 5, 1963 for Electrical Load Distribution Service Center. In this copending application there isdisclosed means for obtaining a threewire branch circuit with plug fuse protection. One of the requirements of such a circuit is that both plug fuses in the circuit must be removed at the same time, and that neither should be independently removable when in circuit. This requirement is made by a receptacle of the type disclosed herein which can be connected through prongs 41 and 42 to two independent bus bars, but which can only be disconnected therefrom by simultaneously disconnecting the receptacle from both bus bars by pulling on handle 27. The co-operation of flaps 46 with a part in the electrical load distribution service centre which engages flaps 46 when the receptacle is in position in the service centre, so as to prevent the pivoting of flaps 46 and cause flaps 46 to remain locked in the closed position, meets the requirement that neither plug fuse be removable independently from openings 12 and 13 when there is a circuit through these fuses. By virtue of openings 48, however, whether or not a fuse has blown is readily determinable, and any blown fuse may be readily replaced by removing the whole receptacle 10 from the service centre, thereby disconnecting the circuits and permitting the opening of flaps 46.

Those skilled in the art will appreciate that while there is disclosed herein preferred embodiments of this invention, many modifications thereof may be made without A departing from the spirit and scope of the invention as defined in the appended claims.

What I claim as my invention is:

1. A receptacle for screw-in overcurrent devices such as plug fuses and the like, said receptacle having a body including side walls and a base, said body having openings therein positioned side-by-side and each adapted to receive a screw-in overcurrent device, said body being divided longitudinally across said openings into two parts each having a part of each of said openings formed therein, a first recess means formed in the side walls of said body defining each opening, a second recess means formed in said base beneath each of said openings, a first electrical con-tact being retained by said first recess means in each of said openings, a second electrical contact means being retained by said second recess means in the base of said openings, said first and second electrical contacts each having first portions adapted to contact different terminals of screw-in overcurrent devices screwed into said openings and second portions adapted to make contact with conductors external to said receptacle, means restraining twisting movement of said body parts relative to each other, means retaining said body parts together, and means mounted on said receptacle and closable over screw-in overcurrent devices screwed into said openings, said closable means in the closed position thereof preventing removal of screw-in overcurrent devices screwed into said openings.

2. A receptacle for screw-in overcurrent devices such as plug fuses and the like, .said receptacle having a body including side walls and a base, said body having openings therein positioned side-by-side and each adapted to receive a screw-in overcurrent device, said body being divided longitudinally across said openings into two parts each having a part of each of said openings formed therein, a first recess means formed in the side walls of said body defining each opening, a second recess means formed in said base beneath each of said openings, at first electrical contact being retained by said first recess means in each of said openings, a second electrical contact means being retained by said second recess means in the base of said openings, said first and second electrical contacts each having first portions adapted to contact different. terminals of scrcw-in overcurrent devices screwed into said openings and second portions adapted to make con tact with conductors external. to said receptacle, means restraining twisting movement of said body parts relative to each other, means retaining said body parts together, and means closable over screw-in overccurent devices comprising members mounted on said receptacle by means of hinges formed by said second portions of said first electrical contacts, said members in the closed position thereof preventing removal of screw-in overcurrent devices screwed into said openings.

3. A receptacle for screw-in overcurrent devices such as plug fuses and the like, said receptacle having a body including side walls and a base, said body having openings therein positioned side-by-side and each adapted to receive a screw-in overcurrent device, said body being divided longitudinally across said openings into two parts each having a part of each of said openings formed therein, a first annular recess means formed in the side walls defining each opening, a second recess means formed in said base beneath each of said openings, a first ringshaped electrical contact being retained by said annular recess means in each of said openings, a second generally U-shaped electrical contact means being retained by said second recess means in the base of said openings, said first and second electrical contacts each having first portions adapted to contact diiferent terminals of screw-in overcurrent devices screwed into said openings and sec; ond portions adapted to make contact with conducting external to said receptacle, means restraining twisting movement of said body parts relative to each other means retaining said body parts together, and means closable over screw-in overcurent devices comprising members mounted on said receptacle by means of hinges formed by said second portions of said first electrical cont acts, said members in the closed position thereof preventing removal of screw-in overcurrent device screwed into said openings, and being provided with apertures through which said screw-in overcurrent devices may be viewed when located in said openings.

4. A receptacle for screw-in overcurrent devices such as plug fuses and the like, said receptacle having a body including side walls and a base, said body having openings therein positioned side-by-s-ide and each adapted to receive a screw-in overcurrent device, said body being divided longitudinally across said openings into two parts each having a part of each of said openings formed therein, a first annular recess means formed in the side walls defining each opening, a second recess means formed in said base beneath each of said openings, a first ringshaped electrical contact being retained by said annular recess means in each of said openings, a second generally U-shaped electrical contact means being retained by said second recess means in the base of said openings, said first and second electrical contacts each having first portions adapted to contact different terminals of screw-in overcurrent devices screwed into said openings and secend portions adapted to make contact with conductors external to said receptacle, means restraining twisting movement of said body parts relative to each other comprising at least one tongue projecting from one of said parts and at least one groove formed in the other of said parts, said tongue being engaged in said groove when said parts are fastened together, a single fastening device retaining said parts together, and means closable over screw-in overcurrent devices comprising members mounted on said receptacle by means of hinges formed by said second portions of said first electrical contacts, said members in the closed position thereof preventing removal of screw-in overcurrent devices screwed into said openings, and being provided with apertures through which said screw-in overcurrent devices may be viewed when located in said openings.

5. A receptacle for screw-in overcurrent devices such as plug fuses and the like, said receptacle having a body including side walls and a base, said body having openings therein positioned side-'by-side and each adapted to receive a screw-in overcurrent device, a first recess means formed in the side walls of said body defining each opening, a second recess means formed in said base beneath each of said openings, a first electrical contact being retained by said first recess means, a second electrical contact means being retained by said second recess means in the base of said openings, said first and second elec trical contacts each having first portions adapted to contact different terminals of screw-in overcurrent devices screwed into said openings and second portions adapted to make contact with conductors external to said receptacle, and means mounted on said receptacle and closable over screw-in overcurrent devices screwed into said openings, said closable means in the closed position thereof preventing removal of screw-in overcurrent devices screwed into said openings.

6. A receptacle for screw-in overcurrent devices such as plug fuses and the like, said receptacle having a body including side Walls and a base, said body having openings therein positioned side-by-side and each adapted to re ceive a screw-in overcurrent device, a first recess means formed in the side walls of said body defining each opening, a second recess means formed in said base beneath each of said openings, =a first electrical contact being retained by said first recess means, a second electrical contact means being retained by said second recess means in the base of said openings, said first and second electrical contacts each having first portions adapted to contact different terminals of screw-in overcurrent devices screwed into said openings and second portions adapted to make cont-act with conductors external to said receptacle, and means closable over screw-in overcurrent devices comprising members mounted on said receptacle by means of hinges formed by said second portions of said first electrical contacts, said members in the closed position thereof preventing removal of screw-in overcurrent devices screwed into said openings.

7. A receptacle for screw-in overcurrent devices such as plug fuses and the like, said receptacle having a body including side Walls and a base, said body having openings therein positioned side-by-side and each adapted to receive a screw-in overcurrent device, a first recess means formed in the side walls of said body defining each opening, a second recess means formed in said base beneath each of said openings, a first electrical contact being retained by said first recess means, a second electrical contact means being retained by said second recess means in the base of said openings, said first and second electrical contacts each having first portions adapted to contact different terminals of screw-in overcurrent devices screwed into said openings and second portions adapted to make contact with conductors external to said receptacle, and means closable over screw-in overcurrent devices comprising members mounted on said receptacle by means of hinges formed by said second portions of said first electrical contacts, said members in the closed position thereof preventing removal of screw-in overcurrent devices screwed into said openings and being provided with apertures through which said screw-in overcurrent devices may be viewed when located in said openings.

References Eited by the Examiner UNITED STATES PATENTS 2,637,764 5/1953 Maxwell 339154 2,701,349 2/1955 Fisher 200-1155 2,756,363 7/1956 Gilday 200-414 2,919,315 12/1959 Woofter 200166 FOREIGN PATENTS 665,218 6/1963 Canada.

BERNARD A. GILHEANY, Primary Examiner. H. B. GILSON, Assistant Examiner. 

5. A RECEPTACLE FOR SCREW-IN OVERCURRENT DEVICES SUCH AS PLUG FUSES AND THE LIKE, SAID RECEPTACLE HAVING A BODY INCLUDING SIDE WALLS AND A BASE, SAID BODY HAVING OPENINGS THEREIN POSITIONED SIDE-BY-SIDE AND EACH ADAPTED TO RECEIVE A SCREW-IN OVERCURRENT DEVICE, A FIRST RECESS MEANS FORMED IN THE SIDE WALLS OF SAID BODY DEFINING EACH OPENING, A SECOND RECESS MEANS FORMED IN SAID BASE BENEATH EACH OF SAID OPENINGS, A FIRST ELECTRICAL CONTACT BEING RETAINED BY SAID FIRST RECESS MEANS, A SECOND ELECTRICAL CONTACT MEANS BEING RETAINED BY SAID SECOND RECESS MEANS IN THE BASE OF SAID OPENINGS, SAID FIRST AND SECOND ELECTRICAL CONTACTS EACH HAVING FIRST PORTIONS ADAPTED TO CONTACT DIFFERENT TERMINALS OF SCREW-IN OVERCURRENT DEVICES SCREWED INTO SAID OPENINGS AND SECOND PORTIONS ADAPTED TO MAKE CONTACT WITH CONDUCTORS EXTERNAL TO SAID RECEPTACLE, AND MEANS MOUNTED ON SAID RECEPTACLE AND CLOSABLE OVER SCREW-IN OVERCURRENT DEVICES SCREWED INTO SAID OPENINGS, SAID CLOSABLE MEANS IN THE CLOSED POSITION THEREOF PREVENTING REMOVAL OF SCREW-IN OVERCURRENT DEVICES SCREWED INTO SAID OPENINGS. 